The present invention relates generally to an electricity consumption counter of the alternating current electric meter, and more particularly to an electronic digital counter of the alternating current meter. The electronic digital counter is capable of converting the data of the electricity consumption into digital signals, which are then transmitted by the electronic digital counter.
The consumptions of the alternating current and the three-phase current by the industry and the private home are measured by the induction-type electric meter, which comprises an electric current magnet 10, a voltage magnet 20, an arresting magnet 30, and a mechanical counter 40, as shown in FIG. 1. The mechanical counter 40 is formed of a metal rotary disk 41 and a gear train counter 42. The metal rotary disk 41 is provided at the center thereof with a center shaft 43 which is pivotally fastened at the bottom thereof with the housing of the alternating current meter. As soon as the power consumption begins, the current flows into the alternation current meter such that the voltage magnet 20 effects a movable magnetic field. The metal rotary disk 41 is induced by the magnetic field of the voltage magnet 20 to turn such that a worm 44 is actuated to turn on the center shaft 43. In view of the worm 44 being engaged with a worm gear 45 of the gear train counter 42, the rotational speed of the metal rotary disk 41 is transmitted to the counter 42. As a result, the numerical data of the revolutions of the metal rotary disk 41 are exhibited by the counter 42. The numerical data represent the power consumption by a client of the power company. It is therefore necessary for the power company to hire a number of persons to record the numerical data described above. Such a practice of the manual recording of the numerical data of power consumption is not cost-effective. In addition, the counter 42 is in fact not reliable in view of the mechanical deficiencies of the electric meter. The function of the counter 42 is carried out by a plurality of gear train sets which are used in the cumulative counting and the number switching. In the transmission process from the metal rotary disk 41 to the counter 42, the mechanical error of the engagement of the gears can take place at any time. The problem is further compounded by the inherent error of the counter 42. The accumulative error can result in a substantial financial loss to either the power user or the power company.
It is the main objective of the present invention to provide an alternating current electric meter with a photoelectric digital counter in place of the conventional mechanical counter which is susceptible to mechanical error.
It is another objective of the present invention to provide an alternating current electric meter which is simple in construction and is free from the error caused by the mechanical transmission.
It is still another objective of the present invention to provide an alternating current electric meter which is small in size, light in weight, and cost-effective.
It is still another objective of the present invention to provide an alternating current capable of transmitting an electronic digital signal to a remote terminal, thereby eliminating the costly man power for the on-site recording of the power consumption by a client of the power company.